Transmitter



May 3,1927.- l 1,626,635 v.,v. sLEPlAN TRANSMITTER' Filed Oct. 28. l9 22= WlTfNEssEs: INVENTOR ATTORNEY'v JOSEPH SLEPIAN, O1? SWISSVALE,

terasse PENNSYLVAIA, ASSIGNOR T 4WESTIINGrIHIOUSE ELECTRIC &MANUFACTUR1G COMPANY, A CORPORATION OF PEN SYLVANIA.

TRANSMITTER.

Application -filed October 28, 192,2. Serial No. 597,561. A

My invention relates to instruments for recording or reproducing sound waves. I One object of my invention is to provide a`soundwave translating devicewhich is 5 characterized by its simplicity of'design and 1trodes 1 and 2, which are connected inv pgation and which lends itself to inexpensiye quantity-production methdsof manufacture, the several parts of which maybe D readily made in existing automatic machin?. be easily assembled with'a.;

ery. and vmay minimum expenditure of time and ot money.l

Another object of myinvention is to provide a translating device Aof the class 'descr1bed,wherein the .sound waves are faith- .fully translated into correspondingly modu-y lated' electrical energy without impalring the quality, tone and quantity of the translated energy.

I have found .that the above-mentioned desired results may be easily and efficiently accomplished by means` of .translating device compiisingapair of spaced electrodes between which a glow discharge is for-med and providing means for varying the spaced 2,5' relation.- of said electrodes in accordance with the varying intensity 'of sound waves.

translating device embodying my invention is based upon the fact that for a givencurrent across the discharge, the voltage drop thereacross varies substantially directly with the length of the discharge.- -It is to be noted, however, that, if the current through the discharge is allowed to vary, as' by em- 35 ploying ahsupply circuit having a relatively small impedance incomparison with that of.

thedischarge, then the current therethrough varies in an'inverse manner v vith.the length of the discharge. Hence, it is seen thatI such 40 devices may 'readily effect thetranslation of sound waves into -correspondinglynddulated energy, all as explained more fully hereinafter. r Y 4 With these and other objects in' view, my

invention further consists in the `ccunbinations, circuit arrangements andmetho'ds of operation'hereinafter more fully set forthe and claimed, and illustrated in the accompanying drawing, wherein f Figure 1 is a view, partially diagrammatic and partially structural, of a preferred arrangement embodying my invention;

Fig. 2 is a very much enlarged 'detail view of tlie discharge electrode shown' in 1.z

the above discharge formed therebetween; l'

l and Fig. 3 is a Aview similar to Fig. 1, but showing a modification.

In Fig. 1 is shown a pair of spaced elecseries-circuitrelation with a stabilizing resistor 3 on-'Qthe'porder of a megohmand a source' 4 'of direct-current ener of 'about 6,000 volts. Thefeect of the resistor Sis to es l 'maintain the current substantiallyconstant,

notwithstanding slight variations inthe impedan'ce'of'th'e circuit including. the same. The spaced 'relation between the' 'l electrodes .1 and 2 may. be .varedinlaccordance with the varyingintensity of the sound waves by mounting one of the,.electrodes, say the posiby Ia certain amount, say one-sixteenth of an.

inch for a system having the constants hereinbefore mentioned, a glow .discharge is formed therebetween comprisi g" the foltive electrodel, upon a telephone transmitn lowing parts arranged respectively between The operation of the above-mentiqneith .Ilegatlve electrode 2 and vthe-'positive electrode 1 g. namely, a cathode glow 8', which timesknown as Crookes dark space; a negative light 11; a Faraday'dark space 12; and

va positiveor anode column 1.; whichv terminates on the positive. electrode 1, all as indicated on a much enlarged scale in Fig. 2.

As previously stated, it has been 'observed that, when the length of the glow discharge' is. varied, as, for instance,- by varying the -dlstance between the electroV es 1 and 2, in

the manner indicated in thedrawing, the potential dropv across theel'ectrodes is correspondingly varied. It is believed that the l greater part oi the potential# variation inci dent to a change in the spacing of theelectrodes is caused by changes in the length of the positive column 13, but my invention is not necessarily limited to such theory of operation.

i The alternating component of voltage -across the electrodes 1 and 2, which is caused by a vibration of the diaphragm 5, may be translated 'into cornespondingly modulated currents by impressing the same through conductors 14`J1and 15 upon the input velecprovision of a supply circuit whic .tubewligfjfcoiitaining, in addition, an anode cludes a source 231of direct-current eV ergy anda coupling coil 24,.. The ampliiied modulated currents traversing the plate-filament Vcircuit are'impressed upon an outgoing orv Working circuit through the coupling coil 24: and the vcoupling coil 26 which is contained inthe latterA circuit. l

l The arrangement shownhin Fig. 3 is distinguished over that shown in Figi. 1in the has such low impedance'that lcurrent variations are produced therein upon the vibration of they electrode L1, rather than potential variations, as lin Fig.. 1./ The supply circuit for the electrodes -1 and 2 now includes a relatively low-voltage source -27 of direct-current energy, and the primary winding 28 of a transformer`29 fortranslating. the current variations in thel supply-circuit-to amplify the p0- tential variations across the terminals of the secondary winding 31 thereof. The potential variations may betranslated into amplied current variations in themanner indicated in the description of Fig. 1. `The operation of'the .modification shown .in.Fig. 2 is otherwise as indicated in Fig. 1. il'

As may readily be seen, a glow discharge has certain inherent characteristics in addition to those pointed out in the foregoing portions of thisspecification which especially fit it for applioatlon to soundfwave translat- .ing devices inV comparison with other forms of discharges, as, for instance, the heatedcathode arc. A few` of the desirable characteristics thereof arel the attainment of relatively cool electrodes, the substantial.

' elimination of vaporization, melting or burning of electrodes, the elimination of a hot s'pot, as is found in the ordinary are, and the steady, smooth and unliuctuating condition of the discharge. The latter is of particu ar importance, inasmuch as the variations 'n the intensity or condition of the dischar' e cause corresponding variations in the p"- tential drop thereacross which, in some cases, may approximate, in magnitude, the potential variations resulting from thediaphragm vibration itself.

While I have shown only two embodiments of my invention and while I have enumeratedcertain specific values in nection therewith,l for the purpose of describing my invention and more fully illus? trating the principles thereof, it is apparent that Various changes'and modifications in -ferred tomay be made Without departing from the spirit of my invention. AI desire,

therefore, thatA only such limitations shall be imposed thereon as are indicated in the appended claims or demanded bythe prior art. v

I c-lalm as my inventlon:

' 1. A translating device comprising a pair of spaced electrodes in the open air, means for maintaining between said electrodes a discharge of t' e character which has a dark space and a owing space and a diaphragm adapted to yibrate inaccordance with the varying intensity. of disturbing impulses, said diaphragm and one `of said electrodes being mechanically 'connected in such manner that @vibration of one is transmitted t0v the otherlg.,

2. In cdinbination, an electrical circuit in cluding a [relatively large substantially constant impedance devicea source of energy and a. relaltively small lvariable impedance device comprising a pair of spaced electrodes in the open air said source of energy and said constant impedance being so proportioned that the discharge between said electrodes is of the character which has a dark space and a glowing space, means' for varying the relative spacing of said electrodes according to va desired frequency, whereby a vibratory electrical quantity is developed in said circuit, and means for translating said vibratory electrical quantity into amplified electrical currents of corresponding vibration frequency.

3. In a sound translating system, a pair of spaced electrodes, means for creating a difference of potential across said electrodes suiiicient of itself to render the space therebetween conducting, and sound controlled means for varyingthe distance between said electrodes.

4. In""a sound translatlng device, a pair `of spaced electrodes open/to the atmosphere,

subscribed my name this 25th day of Oc-4 y tober 1922.

JOSEPH SLEPIAN. 

